Hey everyone,
So I am about 90% sure that I have a tail bitter betta. His fins seem like they are getting shorter however I see no evidence of Fin Rot in esscence of the outer edges. It almost looks like chunks missing from his tail near the ends.
If he is a tail bitter what do I need to do to prevent him from bitting. How can I make him more comfortable. This is my first tail bitter I have ever owned. What should I do?

He could be stressed, bored, or your filter (if you have one) is making it difficult for him to swim. That was what caused one of my male bettas to start biting. He seemed fine with the filter for a couple of months but then it got gunked up and the current got stronger because it was coming out of the overflow area. I treated him in a 1 gallon tank and fixed my filter, and then he was fine for a couple of weeks after I put him back in the filtered tank, but then he started biting again. Sometime soon I want to get a divided 10 or 15 gallon for my current three bettas, and I will put him on the opposite end from the filter where there isn't much water movement.
Otherwise, if you don't have a filter, he could be bored... try adding more plants and decorations, or moving your current ones around- give him a change of scenery. Also put a ping pong ball in his tank. I hear they like playing with those.
Otherwise, if it's from stress, I'm not sure what you could do. Does he have any tank mates that might stress him out? What is his water temp? Is he ever in direct sunlight or is your tank light too bright?
In the meantime you can watch him closely for signs of fin rot and change his water more often, and use Stress Coat when you change his water to help prevent it until his fins heal up.

He doesnt have any tank mates. He is however next to another tank with a betta inside of it. Also his water temp seems to be good. Its at about 74 degrees. He isnt really in the sunlight to much. He just seems sad and I am not sure how to help him. My other fish are fine and stuff but he isnt. Is there anything I could do to make sure that he doesnt get infection since he bitting his tail?

74 is too cold. 76-82 is best. Yes, two degrees does make a big difference.
He could be stressed from seeing another betta.
Warm, clean water (50% water changes every day for 4 days, and then 50% water changes every other day for a few days. another member here advised me of that when my fish started another round of biting) and Stress Coat could help prevent fin rot. I wouldn't treat with aquarium salt unless he actually develops fin rot.

It could be. I never thought of that before. I mean I know that they can get stressed from seeing another betta. But I never had one so stressed that he started bitting. I am definately a worried Mommy.

My betta, Delta, flares and swims on one side of his tank. He thinks he sees another betta but its just him. Then he goes in for a bite on his tail. So I took a piece of white copy paper and taped it to the side he attacks on so it would lesser the chance of him seeing himself. So far it has been a few days now without biting. I do however add aquarium salt to prevent infection and I have heard it helps with the healing process.